Transition dinghy prototype

During the first 6 months of 2009, a prototype has been made of the Transition dinghy, using a modified Fireball dinghy as the starting point. A folding rig of the type described in the competition entry has been made with a 6 sq metre sail, and initial testing has shown it to be practical and efficient.
	1 The floor of the dinghy in front of the centreboard casing was levelled and reinforced with glass fibre cloth and epoxy resin to provide a foundation for the mast foot.
	2 The mast foot was made from plywood and reinforced with glass fibre cloth and epoxy resin. This is a view of the underside, showing the short length of aluminium tubing around which the mast foot rotates.
	3 The upper surface of the mast foot was made with a reinforced slot to receive the lower ends of the two mast struts.
	4 The rotating mast foot is held in place by a stainless steel ring bolted to the floor of the dinghy. Each mast strut is held in place by a through bolt.
	5 As well as being supported by the mast foot, the mast is supported at deck level as it passes through a circular hole in a removable part of the deck. This illustration shows the first step in making the removable deck - a cardboard template was cut to shape.
	6 The rim of the existing deck was moulded using glass fibre cloth and epoxy resin. A piece of fibreboard cut to the shape of the cardboard template was glued in place onto the moulded rim and reinforced on top with glass fibre cloth and epoxy resin.
	7 The rim of the central hole in the new deck piece was thickened and then reinforced with layers of glass fibre and epoxy resin.
	8 When the resin had polymerised, the new deck piece was removed from the dinghy and turned upside down. Reinforcing strips were cut from wood and arranged radially around the central opening. The underside of the deck piece and the reinforcing ribs were coated with glass fibre cloth and epoxy resin.
	9 A slot was cut at the back of the deck piece to allow the mast struts to be slid into place. Metal runners were added to allow the closing section to be slid back into place after the rig has been raised.
	10 This illustration shows the completed mast foot and deck piece with the mast in the raised position. Roller bearings encircle the mast struts to make it easier for them to rotate within the deck opening when the sail is powered up.
	11 This illustration shows the jointed sections of the mast above deck level.
	12 Sail making began with the design of a paper template.
	13 The lower part of the sail was made from two identical laminae between which the mast struts can move during raising and folding of the mast.
	14 The upper part of the sail - above the lowermost batten - was made from a single lamina.
	15 A detail showing how the upper part of the mast sleeve was closed and reinforced.
	16 Simple batten tensioners were made from webbing and Velcro.
	17 A detail showing how the lower end of the mast sleeve was reinforced with webbing.
	18 The completed sail was test-rigged in the garden and battens cut to size.
	19 The first trials on the water were carried out in calm conditions.
	20 Another silhouette view of the rig.